Garden owners who have a specific type of tree are being urged to be vigilant for a small insect that could indicate an infestation. The Forestry Commission has issued a warning about the tree pest known as Ips typographus.

The Commission has stated that due to last year's record dry spring and subsequent heavy rainfall causing waterlogging, lowland spruce trees, especially those on clay soils, are at an increased risk of stress. This could potentially heighten their vulnerability to beetle infestations.

In an alert issued this afternoon, the Forestry Commission advised anyone with spruce trees to watch out for the ips typographus, also referred to as the eight-toothed spruce bark beetle. This beetle is a significant pest of spruce trees in Europe and was first identified in the UK in 2018.

While it typically targets stressed or dying trees, under certain conditions, it can attack healthy trees too. It poses a potential threat to cause substantial damage to Great Britain's forestry and timber industries.

The commission has highlighted that this month marks a period of increased risk as it signals the start of the annual season of beetles blowing over from mainland Europe.

The eight-toothed spruce bark beetle, Ips typographus, is a major pest of spruce trees in the UK, particularly in East and South East England.

This beetle is most commonly found on fallen trees as it tends to prefer stressed and dying trees. However, if the population escalates, the insect will migrate to living trees.

Symptoms include:

• Browning of the crown on live trees.
• Needles becoming lighter in colour, forming mats and often falling to the ground.
• 2-2.5mm entrance holes made by the beetles on the surface of the bark.
• Frass (sawdust-like waste material) produced by feeding larvae can be found on the bark at the base of branches and trunks.

Woodpecker damage is on the rise as these birds strip bark from stems to feast on larvae hidden beneath. Defra's Chief Plant Health Officer, Professor Nicola Spence, has issued a stark warning: "I am urging foresters and landowners to really be on their guard as we enter the heightened risk period for Ips typographus.

"We need maximum vigilance from all landowners and land managers as temperatures rise – the dry spring following last year's wet summer has created ideal conditions for the beetle. The cooperation of the forestry sector has been vital in our efforts to keep the pest at bay and we need that to continue."

But what exactly happens to the trees under attack?

As the weather warms up in late spring and early summer, reaching 11-16 ̊C, male beetles take flight to find new host trees. Upon discovering a suitable tree, a male will drill into it to create a mating chamber and release pheromones to attract females.

Up to four females may respond, with the first female carving out an upward gallery to lay eggs, while others create downward galleries with niches for their eggs, laying between 30 and 80 eggs each.

The real damage occurs when the eggs hatch; larvae expand the niches and dig pupal chambers beneath the bark to pupate. This disrupts the tree's vascular system, leading to branch dieback and potentially killing the entire tree in severe infestations.

Dr Anna Brown from the Forestry Commission has sounded an alert: "Continued vigilance to the threat posed by Ips typographus is needed following the recent rise in temperatures, and we're urging landowners and land managers to report any sightings immediately via Tree Alert to help reduce the risk of the pest spreading. The beetle prefers stressed or dying trees but it can attack healthy trees if the conditions are right."

She further emphasised the importance of collaboration: "The help of the sector is vital in the successful management of this pest – landowners, agents and timber processors should continue to comply with ongoing restrictions for movement of spruce material and methods of forest operations in the Demarcated Area."

Headed by Dr Brown's team at both the Forestry Commission and Forest Research, a rigorous and expansive control programme is in place, seeking to mitigate the potential widespread damage which could affect roughly 725,000 hectares of spruce with an estimated worth of £2.9 billion.

Where has the eight-toothed spruce bark beetle impacted?

The eight-toothed spruce bark beetle is found across mainland Europe and northern Asia.

It has been intercepted at UK ports in the past, but in 2018 it was found in a woodland in Kent. All host trees in the area were removed and incinerated to stop any spread. Eradication efforts were successful but it arrived again in 2021 and is found in multiple locations in Kent and East Sussex.

What to do if you spot the eight-toothed spruce bark beetle

If you spot the signs and symptoms of this pest, report it to the plant health authorities via TreeAlert if you are in Britain or TreeCheck if you are in Northern Ireland.